.container{
    height: 10000px;
    .adv{
        position: fixed;
        top: 20px;
        right: 20px;
        width: 80px;
        height: 100px;
        background-color: red;
        .close{
            position:absolute;
            width: 10px;
            height: 10px;
            right: 0;
            top: 0;
            background-color: yellow;
            text-align: center;
            line-height: 10px;
            padding: 2px;
            cursor: pointer;
        }
    }
    .back{
        position: fixed;
        top: 130px;
        right: 20px;
        width: 80px;
        height: 50px;
        background-color: springgreen;
        display: none;
        color: white;
        text-align: center;
        line-height: 50px;
    }
}